Calibration method for an automated surgical biopsy device

ABSTRACT

A method for calibrating a surgical biopsy system. The biopsy system includes a biopsy instrument and control unit. The biopsy instrument includes a piercer, rotatable cutter, and a port for receiving tissue samples. The method comprises the steps of translating the cutter display until the translation of the cutter is stopped at an extended position and recording the extended position. The cutter is then translated from the extended position proximally until the translation of the cutter is stopped at a retracted position proximal to the extended position. The retracted position is recorded. The method further comprises the step of rotating the cutter to a rotation speed while the cutter is located at the retracted position and, if determined that the rotation speed is within a predetermined rotation speed range, a feedback signal is provided on the display allowing the operator to progress to the next procedural step.

This application is related to the following co-pending U.S. patentapplication: Ser. No. 08/825,899 filed on Apr. 2, 1997. This applicationis further related to the following co-pending U.S. patent applications,which are hereby incorporated herein by reference: Ser. No. 09/543,122filed on Oct. 23, 1998; Ser. No. 09/466,391 filed Dec. 17, 1999; Ser.No. 09/4566,491 filed Dec. 17, 1999. This application claim benefit toProvisional Application 60/222,416 Aug. 2, 2000.

FIELD OF THE INVENTION

The present invention relates, in general, to a method of calibrating abiopsy system and, more particularly, to a method of calibrating thetranslation and rotation of a cutter in a biopsy instrument. The methodmay further be used to determine the correct selection of probe size forthe software installed in the control unit.

BACKGROUND OF THE INVENTION

The diagnosis and treatment of patients with cancerous tumors,pre-malignant conditions, and other disorders has long been an area ofintense investigation. Non-invasive methods for examining tissue includepalpation, X-ray, magnetic resonance imaging (MRI), computed tomography(CT), and ultrasound imaging. When a physician suspects that tissue maycontain cancerous cells, a biopsy may be done using either an openprocedure or a percutaneous procedure. For an open procedure, a scalpelis used to create a large incision in the tissue to provide directviewing and access to the tissue mass of interest. The entire mass(excisional biopsy) or a part of the mass (incisional biopsy) may thenbe removed. In most percutaneous biopsy procedures, a needle-likeinstrument is inserted through a very small incision to access thetissue mass of interest and obtain a tissue sample for later examinationand analysis.

Aspiration and core sampling are two percutaneous methods for obtaininga portion of tissue from within the body. In an aspiration procedure,tissue is fragmented into pieces and drawn through a fine needle in afluid medium. The method is less intrusive than most other samplingtechniques, however, it has limited application since the structure oftissue excised by aspiration is destroyed leaving only individual cellsfor analysis (cytology) and not the tissue structure for analysis(pathology). In core biopsy, a core or fragment of tissue is obtained ina manner, which preserves both the cells and the structure forhistological examination. The type of biopsy used depends mainly onvarious factors, and no single procedure is ideal for all cases. Corebiopsy, however, is very useful in a number of conditions and is widelyused by physicians.

Examples of core sampling biopsy instruments are described in U.S. Pat.Nos. 5,562,822 and 5,769,086 (both issued to Ritchart, et al), and inU.S. Pat. No. 6,007,497 (issued to Huitema). Another example of a coresampling biopsy instrument is the biopsy instrument now marketed byEthicon Endo-Surgery, Inc., Cincinnati, Ohio, under the trade nameMAMMOTOME. Each of these instruments is a type of image-guided,percutaneous, coring, breast biopsy instrument, which uses a vacuum forretrieving tissue samples. A physician uses these instruments to capture“actively” (using the vacuum) tissue prior to severing it from the body.In particular, in these biopsy instruments, tissue is drawn into a portat the distal end of a piercing element, hereinafter referred to as apiercer. A cutting element, hereinafter referred to as a cutter, isrotated and advanced through a lumen of the piercer past the port. Asthe cutter advances through the port, it severs the tissue drawn intothe port from the surrounding tissue. While the cutter is generallyrotated using some type of motor, it may be advanced either manually orautomatically. In the MAMMOTOME instrument, a disposable probe unitcontaining a piercer and cutter is first operationally connected to areusable drive unit. The surgeon can then manually move the cutter backand forth by lateral movement of a knob mounted on the outside of thedrive unit. Once the cutter is in place, proximal to the tissue port,further lateral movement of the knob is prevented and the cutter isadvanced through the tissue port to sever tissue by twisting the knob.This arrangement is advantageous because the surgeon is able, throughtactile and/or audible feedback, to determine whether the cutter iseffectively cutting tissue or if there is a problem, such as binding,stalling, or an obstruction. The surgeon may then adjust the speed atwhich he moves the cutter through the tissue, stop the cutter or backthe cutter away from the tissue. Since the surgeon can feel, throughtactile feedback, at what point the cutter encounters an obstructionsuch as when it has reached its limits of linear travel, he willanticipate these obstructions and can readily control and stop thecutter at its most distal and proximal positions. Anticipating theseobstructions and slowing or stopping the cutter translation just as theobstruction is reached thus avoids undo erratic movement of theinstrument. Manual control of the cutter translation by the surgeontherefore allows the surgeon full control of the rate and distance oflinear travel. Also, since each new disposable probe unit assembled tothe reusable drive unit may vary in length slightly due to manufacturingtolerances, manual control by the surgeon allows for compensation forthese size variations.

U.S. Pat. Nos. 5,562,822 and 5,769,086 describe automation of thetranslation of the cutter in a biopsy device to facilitate theprocedure. However, if the procedure is automated as described in thosereferences, the surgeon loses the benefit of the tactile feedback, whichresults when the cutter is advanced and retracted manually. It wouldtherefore become necessary to require the cutter controlling means toknow the precise condition, location, and travel distance of the cutterto ensure smooth and reliable operation of the biopsy system. In anautomated biopsy system there may therefore be a need for the surgeon tofollow a procedure to calibrate the cutter/probe unit prior to startingthe surgical biopsy to ensure smooth and reliable operation. Such acalibration procedure would also be beneficial in confirming that thesurgeon has selected the correctly sized biopsy probe for the softwareinstalled in the controlling means.

U.S. Pat. No. 6,086,544 (issued to Hibner, et al) describes a controlapparatus for a surgical biopsy device. The biopsy device has a probeunit containing a rotatable, translatable cutter. The drive unitcontains a cutter linear drive screw and cutter rotational drive screw.A control apparatus, containing drive motors, is connected to the driveunit through rotatable, flexible drive cables. A computing device isused to coordinate control of the rotation and linear translation of thecutter. This is accomplished by using optical sensors capable ofproviding very precise rotational position feedback information on thecutter linear drive screw and cutter rotational drive screw. Informationsupplied by these optical sensors to the computing device allows thecomputing device to control individual motors operating the drive cablesconnected to the cutter linear drive screw and cutter rotational drivescrew. The computing device can therefore compare the actual performanceof the biopsy device during the biopsy procedure to pre-establishedperformance parameters and modify motor speeds to maintain systemperformance within pre-established parameters.

This system as disclosed however does not compensate for theaforementioned problem of the surgeon's lack of tactile feedback andcontrol as the cutter reaches its limits of distal and proximal travel.This system reacts to the fact that the cutter's linear travel hasreached its limit after the cutter has encountered a physicalobstruction. Unfortunately the reaction time for the cable rotationalsensors to detect the obstruction, send a message to the controlapparatus, and the control apparatus terminate power to the cable drivemotors may be too long to prevent the flexible, rotatable drive cablesfrom twisting or “winding” do to the cutter's sudden and unexpectedstop. If the user is not grasping the biopsy device tightly there is therisk the biopsy probe could inadvertently move and cause discomfort tothe patent.

Another shortfall of this control system relates to its inability tocompensate for different probe unit/drive unit combinations. Slightvariations in cutter length, cutter position, or probe length occur dueto manufacturing assembly procedures and tolerances. The manufacturermust accept certain manufacturing variations in order to make the devicesafe, functional, and affordable. Therefore, as a new probe unit isoperationally connected to the reusable drive unit at the start of eachbiopsy procedure, the cutter linear travel distance and distal andproximal stopping points will be different from the preceding probeunit/drive unit combination. The probe manufacturer may alsointentionally manufacture different “gauge” probes to different lengthspecifications. The optical sensors could then be used to determine ifthe correctly sized probe is installed to match the software installedin the drive unit. Differently sized or “gauge” probes may therefore bemanufactured to different length specifications so that, upon initialstart-up, the clinician will be warned when an improper probe isinstalled for the software residing in the control unit.

Cutter rotational speed will also vary from one probe unit/drive unitcombination to another due to manufacturing tolerances. It would,therefore, be advantageous to utilize the same optical sensors andcomputing device to establish the relative linear position and travelrange of the cutter at initial start-up. They may also be used toestablish whether or not excessive resistance is present within thecutter/probe unit that would cause the biopsy device to perform outsideof the pre-established performance parameters, even before the biopsydevice is put into actual clinical use.

What is therefore needed is a method in an automated core samplingbiopsy device for determining the cutter's most distal and proximallinear travel position and providing feedback to the cutter controlmeans for the purpose of establishing whether or not the cutter lineardisplacement is within a predetermined range before an actual biopsyprocedure is performed. What is further needed is a method in anautomated core sampling biopsy device for determining the rotationalspeed of the cutter and providing feedback to the cutter control meansfor the purpose of establishing whether or not the cutter rotationalspeed is within a predetermined range prior to a biopsy procedure.

SUMMARY OF THE INVENTION

The present invention is directed toward a method for calibrating asurgical biopsy system. The surgical biopsy system comprises a biopsyinstrument and a control unit. The biopsy instrument comprises anelongated, hollow piercer, and a cutter rotatably and axiallypositionable relative to the piercer. A port is located in the piercerfor receiving tissue samples. The surgical biopsy system comprises acontrol unit and a display for providing feedback signals to anoperator.

A method according to the present invention includes the steps of:translating the cutter distally until the translation of the cutter isstopped at an extended position; recording the extended position;translating the cutter from the extended position proximally until thetranslation of the cutter is stopped at a retracted position proximal tothe extended position; recording the retracted position. The methodfurther comprises the step of rotating the cutter to a rotation speedwhile the cutter is located at the retracted position; determining ifthe rotation speed is within a predetermined rotation speed range;providing a feedback signal on the display allowing an operator toprogress to the next procedural step when the rotation speed is withinthe predetermined rotation speed range.

A method is further disclosed for determining that the correctly sizedbiopsy instrument has been selected by an operator for a surgical biopsysystem The surgical biopsy system comprises a biopsy instrument and acontrol unit. The biopsy instrument comprises an elongated, hollowpiercer, a cutter rotatably and axially positionable relative to thepiercer, and a port in the piercer for receiving tissue samples. Thesurgical biopsy system includes a control unit and a display forproviding feedback signals to an operator.

A method according to the present invention includes the steps of:translating the cutter distally until translation of the cutter isstopped at an extended position; recording the extended position;translating the cutter from the extended position proximally untiltranslation of the cutter is stopped at a retracted position proximal tothe extended position; recording the retracted position; computing inthe control unit total distance traveled between the retracted positionand the extended position by the cutter; providing on the display afeedback signal to the operator when the total distance traveled fallsoutside a predetermined range.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the invention are set forth with particularity inthe appended claims. The invention itself, however, both as toorganization and methods of operation, together with further objects andadvantages thereof, may best be understood by reference to the followingdescription, taken in conjunction with the accompanying drawings inwhich:

FIG. 1 is an isometric view of the present invention, a biopsyinstrument, which includes a handpiece for the collection of softtissue;

FIG. 2 is an isometric view of the handpiece showing a probe assemblyprior to attachment to a holster;

FIG. 3 is an exploded isometric view of the probe assembly illustratedin FIG. 2;

FIG. 4 is an isometric view of the probe assembly of FIG. 2 with theleft handle shell removed to reveal the internal components;

FIG. 5 is an exploded isometric view of the holster illustrating anon-encased rotation sensor mounted on a screw drive shaft;

FIG. 6A is a top view in section of the probe assembly and a distalportion of the holster, revealing a cutter in a first, fully retractedposition;

FIG. 6B is a top view in partial section of the distal end of the probeassembly illustrating the cutter in the first, fully retracted positionwherein the port on the distal end of the piercer is open;

FIG. 7A is a top view in section of the probe assembly and a distalportion of the holster, revealing the cutter in the third positionwherein the distal end of the cutter is immediately proximal to theport;

FIG. 7B is a top view in partial section of the distal end of the probeassembly with the port on the distal end of the piercer open and thedistal end of the cutter in the third position immediately proximal tothe port;

FIG. 8A is a top view in section of the probe assembly and a distalportion of the holster illustrating the cutter in the fourth, fullydeployed position;

FIG. 8B is a top view in partial section of the distal end of the probeassembly illustrating the distal end of the cutter in the fourthposition distal to the port at the distal end of the piercer;

FIG. 9 is an isometric view of the probe assembly with the left handleshell removed, showing the cutter in the first position, with a tissuesample shown deposited onto a tissue sampling surface;

FIG. 10 is a partial top view of a further embodiment of the presentinvention wherein a first and a second motor are contained within ahandheld holster rather than in a remotely located control unit as forthe embodiment of FIG. 5, and wherein the holster upper shell and theprobe assembly upper shell have been removed to reveal the internalcomponents;

FIG. 11 is an isometric view of the holster and probe assembly lowershells shown in FIG. 10, wherein the holster lower shell includes a slotfor the removable attachment to a latch on the probe assembly lowershell;

FIG. 12 is a longitudinal section of the holster and probe assemblylower shells of FIG. 11, illustrating their removable attachment to eachother;

FIG. 13 is an exploded isometric view of a further embodiment of theholster illustrated in FIG. 5, wherein the further embodiment includesthe three switches being mounted on a switch board electricallyconnected by a ribbon cable to the control cord (instead of the threeswitches being electrically connected to the control cord by discreteswitch conductors as illustrated in FIG. 5), and wherein the furtherembodiment includes an encased rotation sensor rather than thenon-encased rotation sensor of the embodiment illustrated in FIG. 5;

FIG. 14 is a schematic diagram of a control unit according to thepresent invention;

FIG. 15 is an enlarged view of an LCD display illustrated in FIG. 14;

FIG. 16A is the first of two portions of a divided schematic diagram ofthe control unit components illustrated in FIG. 14;

FIG. 16B is the second of two portions of the divided schematic diagramof the control unit components illustrated in FIG. 14;

FIG. 17A is a first portion of a flow chart pertaining to a calibrationmethod of a biopsy system according to the present invention,specifically the cutter translation and position;

FIG. 17B is a second portion of a flow chart pertaining to a calibrationmethod of a biopsy system according to the present invention,specifically continuing the cutter translation and position andincluding cutter rotation.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a core sampling biopsy instrument comprising a probeassembly 40, a holster 140, a fluid collection system 22, a control unit342, and a power transmission source 24. Probe assembly 40 is detachablyconnected to holster 140. Together they constitute a lightweight,ergonomically shaped, hand manipulatable portion referred to as ahandpiece 20. Probe assembly 40 includes a piercer 70 extending distallyfrom a hollow handle 43. Probe assembly 40 is fluidly connected to fluidcollection system 22 by a first vacuum tube 94 and a second vacuum tube136. First and second vacuum tubes are detachably connected to fluidcollection system 22 by a first connector 27 and a second connector 25,respectively. First connector 27 has a male portion 32 and a femaleportion 28 attached to first vacuum tube 94. Second connector 25 has afemale portion 30 and a male portion 26 attached to second vacuum tube136. Connector portions, 26, 28, 30, and 32 are attached in this mannerto prevent the accidental switching of first and second tubes, 136 and94, to fluid collection system 22. Holster 140 includes a firstrotatable shaft 34, a second rotatable shaft 36, and a control cord 38.First and second rotatable shafts, 34 and 36, are preferably flexible sothat the operator may easily manipulate handpiece 20 with one hand.Control cord 38 operationally connects handpiece 20 to powertransmission source 24 and control unit 342.

Since handpiece 20 is manipulated by the operator's hand rather than byan electromechanical arm, the operator may steer the tip of handpiece 20with great freedom towards the tissue mass of interest. The surgeon hastactile feedback while doing so and can thus ascertain, to a significantdegree, the density and hardness of the tissue being encountered. Inaddition, handpiece 20 may be held approximately parallel to the chestwall of the patient for obtaining tissue portions closer to the chestwall then may be obtained when using a instrument mounted to anelectromechanical arm.

Those skilled in the art may appreciate that a mount or “nest” could beprovided to hold handpiece 20 securely to the movable arm of an X-raystereotactic table. This would provide the operator with the option touse handpiece 20 to access the tissue mass within the surgical patientin much the same manner as was described earlier for using the MAMMOTOMEinstrument. This versatility may be advantageous to the operator, forexample, in a situation where the handheld imaging device wastemporarily not available for use, and it would be necessary to use theX-ray stereotactic table.

FIG. 2 shows holster 140 and probe assembly 40 separated. A pair of tabs144 project laterally from each side of a holster upper shell 142, andinsert into right and left undercut ledges, 138 and 139 respectively, ofhollow handle 43 of probe assembly 40. A plurality of indentations 66 isprovided on handle 43 to improve the operator's grip on the instrument.A tube slot 162 in lower shell 156 of holster 140 provides clearance forfirst and second vacuum tubes, 94 and 136. A cutter forward switch 146for moving a cutter 96 (see FIG. 3) in the distal direction, a cutterreverse switch 148 for moving cutter 96 in the proximal direction, and avacuum switch 150, are mounted in the distal portion of holster 140 sothat the operator can use handpiece 20 with a single hand. One-handedoperation allows the other hand to be free, for example, to hold anultrasonic imaging device. A ridge 152 on the distal end of holster 140is provided to assist the operator in grasping handpiece 20 and inoperating switches 146, 148, and 150.

Still in FIG. 2, probe assembly 40 includes a window 58 so that aportion of first vacuum tube 94 may be viewed. First and second vacuumtubes, 94 and 136, are made from a flexible, transparent or translucentmaterial, such as silicone tubing. This enables visualization of thematerial flowing through the tubes, 94 and 136. By having window 58 inprobe assembly 40, the operator can see the flow in first vacuum tube 94without needing to look away from the tissue into which piercer 70 isinserted. A transverse opening 68 is provided in the distal end ofhollow handle 43 which allows access from either side to a tissuesampling surface 64. The tissue extracted from the surgical patient isretrieved by the operator or by an assistant from tissue samplingsurface 64.

FIG. 3 is an exploded isometric view of probe assembly 40. Handle 43 isformed from a right handle shell 42 and a left handle shell 44, eachinjection molded from a rigid, biocompatible plastic such aspolycarbonate. Upon final assembly of probe assembly 40, left and righthandle shells, 42 and 44, are joined together by ultrasonic weldingalong a joining edge 62, or joined by any of several other methods wellknown in the art. Probe assembly 40 comprises piercer 70 having anelongated, metallic piercer tube 74 and a piercer lumen 80. On the sideof the distal end of piercer tube 74 is a port 78 for receiving thetissue to be extracted from the surgical patient. Joined alongsidepiercer tube 74 is an elongated, tubular, metallic vacuum chamber tube76 having a vacuum lumen 82. Piercer lumen 80 is in fluid communicationwith vacuum lumen 82 via a plurality of vacuum holes 77 (see FIG. 6B)located in the bottom of the “bowl” defined by port 78. These vacuumholes 77 are small enough to remove the fluids but not large enough toallow excised tissue portions to be removed through first vacuum tube 94(see FIG. 2) which is fluidly connected to vacuum chamber 76. Ametallic, sharpened distal end 72 is attached to the distal end ofpiercer 70. It is designed to penetrate soft tissue such as the breastof a female surgical patient. In this embodiment, sharpened distal end72 is a three-sided, pyramidal-shaped point, although the tipconfiguration may also have other shapes.

Still referring to FIG. 3, the proximal end of piercer 70 is attached toa union sleeve 90 having a longitudinal bore 84 through it, a widenedcenter portion 86, and a transverse opening 88 through widened centerportion 86. Union sleeve 90 is mounted between left and right handleshells, 44 and 42 respectively, on a pair of union sleeve ribs 50 (onlythe rib in the right handle shell is visible) projecting from eachhandle shell. An elongated, metallic, tubular cutter 96 is axiallyaligned within longitudinal bore 84 of union sleeve 90 and piercer lumen80 of piercer 70 so that cutter 96 may slide easily in both the distaland proximal directions. A pair of cutter guides 46 are integrallymolded into each of handle halves, 42 and 44, to slidably retain cutter96 in an co-axially aligned position with the proximal end of piercertube 74. Cutter 96 has a cutter lumen 95 through the entire length ofcutter 96. The distal end of cutter 96 is sharpened to form a cutterblade 97 for cutting tissue held against cutter blade 97 as cutter 96 isrotated. The proximal end of cutter 96 is attached to the inside of acutter gear bore 102 of a cutter gear 98. Cutter gear 98 may be metallicor polymeric, and has a plurality of cutter gear teeth 100, each toothhaving a typical spur gear tooth configuration as is well known in theart.

Still in FIG. 3, cutter gear 98 is driven by an elongated drive gear 104having a plurality of drive gear teeth 106 designed to mesh with cuttergear teeth 100. The function of drive gear 104 is to rotate cutter gear98 and cutter 96 as they translate in both longitudinal directions.Drive gear 104 is preferably made from a metal such as stainless steel.A distal drive axle 108 projects from the distal end of drive gear 104and mounts into an axle support rib (not visible) molded on the insideof left handle shell 44. A gear shaft 110 projects from the proximal endof drive gear 104 and is supported by a gear shaft support rib (notvisible) also molded on the inside of left handle shell 44. A left crosspin 112 is attached to the proximal end of gear shaft 110 as a means forrotationally engaging drive gear 104.

Still referring to FIG. 3, a carriage 124 is provided to hold cuttergear 98 and to carry cutter gear 98 as it is rotated in the distal andproximal directions. Carriage 124 is preferably molded from a rigidpolymer and is cylindrically shaped with a threaded bore 126 through itand with a carriage foot 130 extending from its side. Carriage 124contains a distal carriage wall 123 and proximal carriage wall 125, eachlocated on opposite faces of carriage 124 and oriented at approximatelyninety degrees to the axis of threaded bore 126. Carriage foot 130 has arecess 128 formed into it for rotatably holding cutter gear 98 in theproper orientation for cutter gear teeth 100 to mesh properly with drivegear teeth 106. Carriage 124 is attached via threaded bore 126 to anelongated screw 114, which is parallel to drive gear 104. Screw 114 hasa plurality of conventional lead screw threads 116 and is preferablymade from a stainless steel. The rotation of screw 114 in one directioncauses carriage 124 to move distally, while the reverse rotation ofscrew 114 causes carriage 124 to move proximally. In turn cutter gear 98moves distally and proximally according to the direction of the screwrotation, and cutter 96 is advanced or retracted. In this embodiment,screw 114 is shown with a right hand thread so that clockwise rotation(looking from the proximal to distal direction) causes carriage 124 totranslate in the proximal direction. It is also possible to use aleft-hand thread for screw 114 as long as provisions are made to do soin control unit 342. A distal screw axle 118 and a proximal screw shaft120 project from the distal and proximal ends, respectively, of screw114. Distal screw axle mounts rotatably in a distal screw support 48 ofright handle shell 42 while proximal screw shaft 120 mounts rotatably ina proximal screw support 54, also in right handle shell 42. Distal screwsupport 48 contains distal screw support wall 49, which is parallel todistal carriage wall 123. Proximal screw support 54 contains proximalscrew support wall 55, which is parallel to proximal carriage wall 125.A right cross pin 122 is attached to the proximal end of screw shaft 120as a rotational engagement means.

At this point in the detailed description, it is important to point outthat during operation of the present invention, cutter 96 translates ineither direction between a fully retracted position just proximal totissue sampling surface 64 and a fully deployed position just distal toport 78 (see FIG. 4). There are key intermediate positions along thelength (about six inches for this particular embodiment) of the cuttertranslation. When the distal end of cutter 96 reaches each of thesepositions, important adjustments to either the cutter rotational speed(sometimes referred to simply as rotation speed) or the cuttertranslational speed (sometimes referred to simply as translation speed),or both, are made automatically. For the embodiment of the biopsy devicedescribed herein, there are four positions along the length of thecutter translation. At these positions, signals to control unit 342 aresent in order to make appropriate adjustments to cutter rotational speedand/or cutter translational speed. To facilitate description of thecutter positions, they are to be understood as actually the positions ofcutter blade 97 on the distal end of cutter 96. These four cutterpositions are the following: a first position where cutter 96 is justproximal to the tissue sampling surface 64 (see FIG. 6B); a secondposition where cutter 96 is just distal to tissue sampling surface 64(in FIG. 6B, cutter blade 97 would be located to the left of tissuesampling surface 64 instead of to the right); a third position wherecutter 96 is just proximal to port 78 (see FIG. 7B); and a fourthposition where cutter 96 is just distal to port 78 (see FIG. 8B). Thesefour cutter positions are given by way of example although numerousother cutter positions may be used in the present invention forautomatically signaling adjustments to cutter rotational speed and/ortranslational speed. These four positions are sometimes referred to as aposition one, a position two, a position three, and a position four.They are also referred to as a position 1, a position 2, a position 3,and a position 4.

Probe assembly 40 is detachably connected to holster 140. Probe assembly40 and holster 140 are separable so that, in the case of the probe beingmanufactured as a reusable structure, the entire probe assembly 40 maybe disassembled, cleaned, reassembled, and sterilized prior to reuse. Inthe case of the probe being manufactured as disposable, the entire probeassembly 40 may be properly disposed of. The fact that these twocomponents are separable requires that a calibration procedure beperformed each time a probe assembly 40 and holster 140 are mated.

It should be noted here that different diameter or “gauge” probes may beintentionally manufactured to different lengths. By specifying aspecific length for piercer 70, a unique cutter translation distance maybe programmed into control unit 342 software for specific probe gauges.This will aid in identifying, at start-up, that the proper probe hasbeen selected for the software loaded in the control unit, as will bedescribed in more detail later.

Alternately, the pitch of screw threads 116 on screw 114 may bespecified differently for different gauge probes. The translationdistance for cutter 96 is determined in control unit 342, as isdescribed in more detail later, by counting the number of revolutions ofscrew 114. As the pitch of screw threads 116 is increased or decreased,the linear distance traveled by cutter 96 is increased or decreased pereach revolution of screw 114. Different pitch threads specific to probegauge can therefore be used to effect cutter translation distance. Thisinformation is communicated to control unit 342 and can be used todetermine if the correct gauge probe is selected for the software loadedin control unit 342, as will be described in more detail later.

Now referring again to FIG. 3, the distal end of first vacuum tube 94 isattached to a polymeric vacuum fitting 92 which inserts tightly intotransverse opening 88 of union sleeve 90. This allows the communicationof fluids in piercer lumen 80 to fluid collection system 22. Firstvacuum tube 94 is contained within hollow handle 43 in an open spaceabove screw 114 and drive gear 104, and exits the distal end of hollowhandle 143 through an opening 57. Second vacuum tube 136 is fluidlyattached to the proximal end of an elongated, metallic, tubular tissueremover 132. Second vacuum tube 136 exits hollow handle 43 alongsidefirst vacuum tube 94 out the opening 57. A strainer 134 is attached tothe distal end of tissue remover 132 to prevent the passage offragmented tissue portions through it and into fluid collection system22. Tissue remover 132 inserts slidably into tubular cutter 96. Duringoperation of the biopsy instrument, tissue remover 132 is alwaysstationary and is mounted between a pair of proximal supports 52 on theinside of the right and left handle shells, 42 and 44 respectively. Whencutter 96 is fully retracted to the first position, the distal end oftissue remover 132 is approximately even with the distal end of cutter96. The distal end of cutter 96 when at its first, fully retractedposition, is slightly distal to a vertical wall 69 which is proximal andperpendicular to tissue sampling surface 64.

In FIG. 3, a right access hole 56 is shown in the proximal end of righthandle shell 43. Right access hole 56 provides access to the proximalend of screw 114 for operational engagement to power transmission source24. Similarly, a left access hole (not shown) is provided in left handleshell 44 to provide access to the proximal end of drive gear 104 foroperational engagement with power transmission source 24.

Tissue remover 132 has two functions. First, it helps to evacuate fluidscontained in piercer lumen 80. This is accomplished by the attachment ofsecond vacuum tube 136 to the proximal end of tissue remover 132. Sincethe distal end of tissue remover 132 is inserted into piercer lumen 80,piercer lumen 80 is fluidly connected to fluid collection system 22.Second, tissue remover 132 removes tissue from cutter 96 as follows.When a tissue sample is taken, cutter 96 advances to the fourth positionjust distal to port 78, and a severed tissue sample 200 (see FIG. 9) iscaptured within cutter lumen 95 in the distal end of cutter 96. Thencutter 96 translates to the first position so that cutter blade 97 isjust distal to tissue sampling surface 64. At this position of cutter96, the distal end of tissue remover 132 (which is always stationary) isapproximately even with the distal end of cutter 96. Therefore, anytissue portion of significant size contained within cutter lumen 95 ispushed out of cutter lumen 95 and onto tissue sampling surface 64, as isshown in FIG. 9. The operator or an assistant may then retrieve tissuesample 200.

Now turning to FIG. 4, an isometric view of probe assembly 40 with lefthandle shell 44 removed reveals the placement of the componentsdescribed for FIG. 3. Part of first vacuum tube 94 has also been removedfor clarity. Carriage 124 is shown in the fully retracted position sothat cutter 96 is also at the fully retracted or first position. Cutterblade 97 is slightly distal to vertical wall 69 on handle 43. Carriagefoot 130 of carriage 124 is adapted to slide along a carriage guidesurface 60 on the inside bottom of hollow handle 43.

As shown in FIG. 4, a cutter translational transmission 121 includescarriage 124, screw 114, and screw shaft 120. A cutter rotationaltransmission 109 includes drive gear 104, cutter gear 98, and gear shaft110.

FIG. 5 is an exploded isometric view of holster 140. A holster uppershell 142 and a holster lower shell 156 are each injection molded from arigid, biocompatible plastic such as polycarbonate. Upon final assembly,the shells are joined together by screws (not shown) or other types offasteners well known in the art, into a plurality of alignment holes164. A gear drive shaft 180 and a screw drive shaft 182 are containedwithin the proximal, enclosed portion of holster 140. These shaftsextend from a grommet 176 which has a groove 172 for retainably mountingonto shell edge 170 of both holster upper and lower shells, 142 and 156,respectively. Grommet 176 rotatably attaches first rotatable shaft 34 toscrew drive shaft 182 and second rotatable shaft 36 to gear drive shaft180. First rotatable shaft 34 rotatably inserts into a left bore 172 ofgrommet 176. Second rotatable shaft 36 rotatably inserts into a rightbore 178. Grommet 176 also provides a strain-relieved attachment ofcontrol cord 38 to holster 140.

Still referring to FIG. 5, gear drive shaft 180 is supported rotatablyupon a pair of gear drive mounts 160 formed into a first wall 166 and asecond wall 168 of the inside of holster shells, 142 and 156. Screwdrive shaft 182 is likewise supported rotatably on screw drive mounts158. A left coupler 184 is attached to the distal end of drive gearshaft 180 and has a left coupler mouth 192 for rotational engagementwith left cross pin 112 attached to gear shaft 110. When probe assembly40 shown in FIG. 4 is attached to holster 140, gear shaft 110 becomesrotatably engaged to gear drive shaft 180. This may be seen more clearlyin FIG. 6A. Similarly, screw drive shaft 182 has a right coupler 186with a mouth 194, which rotatably engages with cross pin 122 of screwshaft 120. Each of the left and right couplers, 184 and 186, have acoupler flange, 188 and 190, which rotatably insert into thrust slots159 formed into the corresponding portions of drive mounts 158 and 160.Coupler flanges, 188 and 190, bear the translational loading of driveshafts, 180 and 182.

Still referring to FIG. 5, holster 140 further includes an non-encased,rotation sensor 198 for providing an electronic signal to control unit342 to be described later. A suitable example of an non-encased rotationsensor 198 is an optical encoder, Part Number HEDR-81002P, availablefrom the Hewlett-Packard Corporation. In this first embodiment,non-encased rotation sensor 198 is mounted within the inside of holsterupper shell 142 and in a position directly above screw drive shaft 182.A fluted wheel 199 is attached to screw drive shaft 182 and extends infront of a light emitting diode contained within non-encased rotationsensor 198. As fluted wheel 192 rotates, the interrupted light beams areelectronically detected and transmitted back to control unit 342 toprovide information about the rotational speed of screw drive shaft 182.By counting the number of screw rotations from the beginning ofoperation, the instantaneous axial translation position and speed ineither direction of cutter 96 may be calculated by control unit 342.Non-encased rotation sensor leads 196 pass through grommet 176 and arepart of the bundle of conductors within control cord 38.

Holster 140 shown in FIG. 5 has forward, reverse, and vacuum switches,146, 148, and 150 respectively, mounted on the inside of holster uppershell 142. Switches 146, 148, and 150 are electronically connected to aplurality of conductors 193 contained in control cord 38. Vacuum switch150 operates fluid communication with fluid collection system 22 andalso sets control unit 342 to respond to various commands as describedlater. Reverse switch 148 operates the movement of cutter 96 in theproximal direction and sets control unit 342 to respond to variouscommands. Forward switch 150 operates the movement of cutter 96 in thedistal direction and sets control unit 342 to respond to variouscommands. The physical locations of switches, 146, 148, and 150 onhandpiece 20 are not restricted to the locations depicted in FIG. 2.Other embodiments of handpiece 20 of the present invention mayincorporate certain ergonomic or other considerations, and switches 146,148, and 150 may be located elsewhere. In addition, switches 146, 148,and 150 may be of varying shapes and colors, or have varying surfacetreatments, so as to distinguish from one another, and to assist theoperator in differentiating each one from the others either by tactileor visual identification.

As already described, FIGS. 6A through 8A depict three of the fourpositions of cutter 96 during the operation of the present invention asembodied in the prior FIGS. 1-5. The three positions are most easilydistinguished by observing the relative positions of carriage 124 (whichmoves together with cutter 96) and cutter blade 97 on the distal end ofcutter 96.

In FIGS. 6A and 6B, cutter 96 is at the first position. Carriage 124begins its translation on the proximal ends of drive gear 104 and screw114. Cutter blade 97 is shown to be immediately proximal to tissuesampling surface 64. In the first position, tissue sample 200 may beretrieved from tissue-sampling surface 64 (see FIG. 9).

In FIGS. 7A and 7B, cutter 96 is at the third position. Carriage 124 isshown to have translated to the intermediate position that is a shortdistance from the distal ends of screw 114 and drive gear 104. Cutterblade 97 is shown by hidden lines to be located just proximal to port78. Vacuum holes 77 are open to port 78 so that soft tissue adjacent toport 78 can be pulled into port 78 when first vacuum tube 94 is fluidlyconnected to the vacuum of fluid collection system 22.

FIGS. 8A and 8B show cutter 96 at the fourth position. Carriage 124 islocated near the distal ends of screw 114 and drive gear 104. Cutterblade 97 is shown now (by hidden lines) to be distal to port 78 and tobe covering vacuum holes 77. The tissue pulled into port 78 will havebeen severed by the rotating, advancing cutter blade 97 and storedinside cutter lumen 95 of the distal end of cutter 96. When cutter 96retracts back to the first position as shown in FIGS. 6A and 6B, tissuesample 200 may be retrieved as shown in FIG. 9.

FIG. 10 shows a further embodiment of the present invention, includingan integrally motorized holster 221. The main difference from theembodiment of holster 140 shown in FIG. 5 is that integrally motorizedholster 221 contains a first brushless, electric motor 234 and a second,brushless electric motor 236. A suitable example for first and secondbrushless, electric motors, 234 and 236, is Part Number B0508-050,available from Harowe Servo Controllers, Incorporated. In the embodimentof FIG. 10, rotatable shafts 34 and 36 have been eliminated so that onlya control/electrical power cord 232 is required to electrically connectintegrally motorized holster 221 to power transmission source 24 andcontrol unit 342 (see FIG. 1). A holster lower shell 222 has a firstwall 242 and a second wall 244, which are spaced apart and adapted tosupport the pair of brushless, electric motors, 234 and 236, in aside-by-side arrangement. The use of brushless, electric motors, 234 and236, eliminates the need for a separate rotation sensor to be mounted inthe drive train of one or both of a screw 206 and a drive gear 204 aswas described for holster 140 shown in FIG. 5. As for holster 140 ofFIG. 5, when a probe assembly 202 is attached to integrally motorizedholster 221, a right coupler 238 rotationally engages a right cross pin214 of a screw shaft 210. A left coupler 240 rotationally engages a leftcross pin 216 of a gear shaft 212. An attachments slot 233 in holstershell 222 retains a grommet 230 having a grommet groove 231. Fastenerholes 228 are provided to fasten holster lower shell 222 to a holsterupper shell (not shown) using screws or other types of fasteners wellknown in the art.

Another difference of integrally motorized holster 221 shown in FIG. 10from holster 140 shown in FIG. 5 is that probe assembly 202 comprises alower shell 208 and an upper shell (not shown). Hollow handle 43 ofholster 140 shown in FIG. 5, however, is divided vertically into leftand right shells, 44 and 42 respectively. This arrangement facilitatesthe mounting of brushless motors, 234 and 236, and additional featuresdescribed next.

FIG. 11 shows an isometric view of probe lower shell 208 and holsterlower shell 222 of integrally motorized holster 221 illustrated in FIG.10. The view in FIG. 11 is upside-down with respect to the view in FIG.10 in order to show a probe latch 220 molded into probe lower shell 208.Probe latch 220 is a cantilever beam and can be deflected downwards by aforce applied to a latch ramp surface 223. Probe latch 220 furthercomprises a latch projection 219 for insertion into a holster slot 224as probe assembly 202 is inserted into integrally motorized holster 221.Ramp surface 223 is deflected downwards by interaction with an insidesurface 225 of holster shell 222 and retainably snaps into a slot key226 when probe assembly 202 is fully inserted into integrally motorizedholster 221. By engaging probe latch 220 in this way, the left and rightcouplers, 240 and 238, rotationally engage to drive shaft 212 and gearshaft 210, respectively, as shown in FIG. 10. To remove probe assembly202 from integrally motorized holster 221, the operator presses onprojection 219 while pulling them apart. FIG. 12 shows a longitudinalsection through the center axis of probe lower shell 208 and holsterlower shell 222 of FIG. 11 for when they are fully attached together.

FIG. 13 is an exploded isometric view of a further embodiment of thepresent invention that includes a switchboard 274 integrally mountedinside of a switch board-modified holster 251. Switch board-modifiedholster 251 may be used with probe assembly 40 shown in FIGS. 1-4. Afirst rotatable shaft 264 and a second rotatable shaft 266 are eachattached by a grommet 262 to a drive shaft 258 and a screw shaft 260,respectively. Rotatable shafts, 264 and 266, are preferably flexibletoo, in order for switch board-modified holster 251, together with probeassembly 40 (see FIG. 2), to be easily manipulatable with one hand. Anencased rotation sensor 268 (also referred to as a third sensor) isshown mounted on a screw shaft 260. A suitable example for encasedrotation sensor 268 is a miniature optical encoder, which iscommercially available as Model Number SEH17 from CUI Stack,Incorporated. It is electrically connected to a switchboard 274 whichmounts to the inside of holster upper shell 252. Switchboard 274 alsohas a ribbon cable 270 containing a plurality of conductors forconveying electronic information to and from control unit 342. Switchboard 274 has mounted on its distal end, three switches, 276, 278, and280, for operation of the present invention in the same manner asdescribed for holster 140 of FIG. 5: a vacuum switch 280 for fluidicconnection to the vacuum of fluid collection system 22; a forward switch276 for the forward movement of cutter 96; and a reverse switch 278 forthe reverse movement of cutter 96. Switches 276, 278 and 280 projectthrough three switch openings 254 of holster upper shell 252. A holsterlower shell 256 attaches to upper shell 252 as in the other embodimentsto enclose the components of the proximal portion of holster 251. It iswell known in the art that controls for a surgical instrument such asdescribed in the embodiments herein may be incorporated into a footoperable mechanism in order to free the hands of the operator.

FIG. 14 is a schematic diagram which illustrates the interconnection ofthe electro-mechanical components of the biopsy device to control unit342. FIG. 14 illustrates the biopsy device illustrated in FIG. 1 andcomprises control unit 342, fluid collection system 22, powertransmission source 24, and handpiece 20 (see FIG. 1). A more detailedschematic diagram illustrating the elements of control unit 342 is shownin FIGS. 16A and 16B and will be described later. All of the componentsof FIG. 14 may be packaged into a portable, wheeled unit, and moved fromroom to room such as in a physician's office. Handpiece 20 (see FIG. 1),as described earlier, may be mounted to a stereotactic table already inthe room, or handheld and used in combination with a handheld imagingdevice such as a handheld ultrasonic imager. Each time the biopsy deviceis used for a new patient, a new sterile probe assembly 40 may be usedin handpiece 20.

In particular, FIG. 14 illustrates the interconnection of switchboardmodified holster 251 with control unit 342, and the connection of powertransmission source 24 to control unit 342. In the embodiment of theinvention illustrated in FIG. 14, power transmission source 24 comprisesa rotation motor 338 and a translation motor 340. Rotation motor 338 andtranslation motor 340 transmit rotational power to switchboard-modifiedholster 251 via first and second rotatable shafts, 264 and 266,respectively. An example of a motor which is suitable for eitherrotation motor 338 or translation motor 340 is available from MicroMotors Electronics, Incorporated, as DC Micro Motors Series 3863, withintegral, miniature optical encoder, Part Number SHE 17. Rotation motor338 has an integral rotation sensor also referred to as a first sensor.Translation motor 340 has an integral rotation sensor also referred toas a second sensor.

By having encased rotation sensor 268, as shown in FIG. 14, mounted inswitchboard modified holster 251, it is possible for control unit 342 tocalculate the amount of twisting along the length of second rotatableshaft 266 by comparing the output of the encoder of translation motor340 to the output of encased rotation sensor 268. Since the number ofrevolutions of rotatable shaft 266 is used to determine where cutter 96is located axially, this twisting could cause significant error,especially if rotatable shaft 266 is very long. This error could result,for example, in cutter 96 not stopping immediately when translationmotor 340 is turned off, because first rotatable shaft 266 is continuingto “unwind”. As a result, control unit 342 uses the signals from theintegral rotation sensor (also referred to as the first sensor) oftranslation motor 340 and encased rotation sensor 268 to calculateaccurately the axial position of cutter 96.

Second rotatable shaft 266 runs parallel to first rotatable shaft 264between control unit 342 and holster 251. The mechanical efficiency ofeither shaft in transmitting rotation from the respective motor toholster 251 varies to some degree with the orientation of the rotatableshaft. If for example, it is necessary during the surgical procedure forthe operator to drape first and second rotatable shafts, 264 and 266, sothat they are bent significantly, then there will be more frictionalenergy losses than if the shafts were straight. In one embodiment of thepresent invention, if the initial current supplied to rotation motor 338is not sufficient to attain a predetermined cutter rotational speed, thecurrent to rotation motor 338 increases until a desired rotational speedis reached. The rotation sensor integrated into rotation motor 338provides feedback signals to control unit 342, so that the compensatingcurrent can be supplied to rotation motor 338. Once the desiredrotational speed is reached, the current to rotation motor 338 is“locked” until cutter 96 reaches position four at the end of itstranslation. This electrical compensation occurs for each time cutter 96translates between the second and third positions, before cutter 96begins to cut tissue. This allows for variations in the way rotatableshafts, 264 and 266, are oriented for each time the operator positionsthe biopsy instrument for collecting a tissue sample.

Referring now to fluid collection system 22 shown in FIG. 14, fluidcollection system 22 comprises a first valve 314, a second pinch valve316, a fluid collection canister 318, a regulator valve 322, a pressuresensor 328, and a vacuum pump 330. These components are interconnectedto each other, control unit 342, and probe assembly 40 (FIG. 1) asfollows. First vacuum tube 94 comes from probe assembly 40 (FIG. 1), andis attached to a first vacuum Y-connector 302 which is fluidly connectedto a first upper line 306 and a first lower line 308. The two lines, 306and 308, pass through first pinch valve 314. An example of a suitable,commercially available, three-way pinch valve for this application isModel Number 373 12-7 15, available from Angar Scientific Company,Incorporated. Pinch valve 314 closes either the first upper line 306 orthe first lower line 308, but never both lines simultaneously. Firstlower line 308 provides a vent to atmospheric pressure. First upper line306 attaches to fluid collection canister 318. Similarly, second vacuumline 136 from probe assembly 40 attaches to a second Y-connector 304which is fluidly connected to a second upper line 310 and a second lowerline 312. The first and second vacuum Y-connectors, 302 and 304, may bemolded from a rigid polymer such as polycarbonate. Second upper line 310passes through a second pinch valve 316, which is identical to thefirst, and to canister 318. Second lower line 312 passes through secondpinch valve 316 and vents to the atmosphere. Again, only one or theother of the two lines, 310 and 312, may be pinched closed at any time.

Still referring to fluid collection system 22 of FIG. 14, a main vacuumline 320 attaches canister 318 to electrically powered vacuum pump 330.An example of a suitable vacuum pump for this application is availableas WOB-L PISTON Series 2639 from Thomas Compressors and Vacuum Pumps,Incorporated. Main vacuum line 320 passes through regulator valve 322 toadjust electronically the vacuum pressure supplied to canister 318. Anexample of a commercially available regulator valve for this applicationis model number VSONC6S11VHQ8 from Parker Hannifin Corporation,Pneutronics Division. Pressure sensor 328 is fluidly attached to mainvacuum line 320 at a sensor connection 324. The signal from pressuresensor 328 is sent to an A/D converter 396 of control unit 342. Anexample of a commercially available, compensated pressure sensor forthis application is model number SDX15 from SenSym, Incorporated.

In FIG. 14 control unit 342 is shown to include the elements inside thedrawn box, a liquid crystal display (LCD) 334, and a touchscreen 336.FIGS. 16A and 16B together form a detailed schematic of the elements ofcontrol unit 342. FIGS. 14, 16A, and 16B may be referred to concurrentlyfor the description of the elements of control unit 342. At the heart ofcontrol unit 342 is a microprocessor 408. An example of a suitablemicroprocessor 408 is 40 MHz, 32-bit microprocessor, available fromMotorola, Incorporated as Part Number XCF5206EFT40. Microprocessor 408is designed to perform logic operations that may be translated intosimple electromechanical actions. LCD 334 prompts and informs theoperator during the operation of the biopsy device. A suitable examplefor LCD 334 is 640×480 color TFT-LCD display available from SharpElectronics Corporation as part number LQ64D343. A resistive touchscreen 336 covers LCD 334 for the user interface. An example of asuitable touch screen 336 is available from Dynapro Thin Film Products,Incorporated as Part Number 95638. LCD 334 is electronically connectedto a touch screen controller 402 in control unit 342.

Interfacing with microprocessor 408 is an oscillator 540, an EPROM 542,and a voltage supervisor 541. Oscillator 540 is available, for example,as Part Number ASV-40.000000-PCSA (40 megahertz) from AbraconCorporation. A suitable example for EPROM 542 is Part NumberAT27BV4096-15JC available from Atmel Corporation. A suitable example forvoltage supervisor 541 (for a 2.93-volt supply) is available as PartNumber TLC773ID from Texas Instruments, Incorporated.

Touch screen controller 402 allows control unit 342 to respond to theuser's touch by interpreting touch inputs. Other more conventionaldevices, such as mechanical switches, may be used instead of touchscreen controller 402 for controlling control unit 342. Touch screencontroller 402, however, is easy to keep clean and is intuitive for theoperator to use. Touch screen controller 402 comprises a microcontroller511, an A-D converter 512, a multiplexer-demultiplexer 513, and anEEPROM 514. A suitable example for microcontroller 511 is 8-bitmicro-controller Part Number 95705 from Microchip Technology,Incorporated. A suitable example for A-D converter 512 is 10-bit serialA-D converter Part Number TLV1543CDW from Texas Instruments,Incorporated. A suitable example for multiplexer-demultiplexer 513 isdual 4-to-1 line analog multiplexer-demultiplexer Part NumberMC74HC4052D from Motorola, Incorporated. A suitable example for EEPROM514 is 1K-bit serial EEPROM Part Number 93AA46SN from MicrochipTechnology, Incorporated.

A LCD controller 404 is provided to interface between microprocessor 408and LCD 334. LCD controller 404 reduces the burden of microprocessor 408by efficiently controlling display parameters such as color, shading,screen update rates, and it typically accesses the memory chips ofmicroprocessor 408 directly. LCD controller 404 comprises a 25-megahertzoscillator 539 that is available, for example, as part numberASV-25.000000-PCSA from Abracon Corporation. LCD controller 404 alsocomprises an LCD/CRT controller 508 that is available, for example aspart number SED1354FOA from Seiko Epson Corporation, and a 1-meg×16-bit, 60 nanosecond, EDO DRAM 507 that is available, for example, aspart number MT4LC1M16E5TG-6 from Micron Technology, Incorporated. LCDcontroller 404 further comprises a pair of 16-bit drivers, 509 and 510,of the non-inverting, buffer-line type, that are available, for example,as part number 74ACTQ16244SSCX from National Semiconductor Corporation.

A miniature annunciator 332 is provided with control unit 342 in orderto provide the operator with audible feedback “beeps” upon eachactivation of an icon control on LCD 334. An example of a suitableannunciator for this application is model number EAS-45P104S fromMatshusita Electric Corporation of America (Panasonic Division).Annunciator 332 interfaces with microprocessor 408 by an oscillator 400which converts the digital input signal from microprocessor 408 to ananalog, periodic output signal, thus controlling the audio frequency ofannunciator 332. The volume of the sound coming from annunciator 332 iscontrollable, as will be described later. Referring to FIG. 16B,oscillator 400 comprises a 62dB audio attenuator 517 that is available,for example, as Part Number LM1971M from National SemiconductorCorporation. Oscillator 400 further comprises an operational amplifier516 that may be identical, for example, to operational amplifier 530already described. Oscillator 515 further comprises a power audioamplifier 515 that is available, for example, as part number LM486M fromNational Semiconductor Corporation.

Still referring to control unit 342 shown in FIGS. 14, 16A and 16B, afirst motor controller and driver 390 interfaces with translation motor340 and with microprocessor 408. Translation motor 340 is operationallyconnected to second rotatable shaft 266. Controller and driver 390converts digital input signals from microprocessor 408 into analog motorinput signals for controlling motor rotational direction and speed.Closed loop digital speed control of translation motor 340 is alsoachieved within controller and driver 390 using feedback signals fromencased rotation sensor 268 in holster 251 and rotation sensorintegrated within translation motor 340. First motor controller anddriver 390 comprises a first H-bridge motor driver 552 (also referred toas a first driver) and a first motor controller 523. A suitable exampleof a first H-bridge motor driver is available as Part Number LMD18200Tfrom National Semiconductor Corporation. A suitable example of a motorcontroller is available as Part Number LM629M-8 from NationalSemiconductor Corporation.

Still referring to FIGS. 14, 16A, and 16B, rotation motor 338 drivesfirst rotatable shaft 264. Rotation motor 338 interfaces withmicroprocessor 408 through second controller and driver 406 whichcomprises a second H-bridge motor driver 551 (also referred to as asecond driver) and a second motor controller 522. Second H-bridge motordriver 551 may be identical to first H-bridge motor driver 552, alreadydescribed. Second motor controller 522 may be identical to first motorcontroller 523, already described. Microprocessor 408 via secondcontroller and driver 406 continually calculates and updates therotational positions of cutter 96, as well as the rotational speed andacceleration, using feedback signals from the rotation sensor integratedwithin rotation motor 338.

Still referring to control unit 342 shown in FIGS. 14, 16A, and 16B, aserial controller 380 is electronically connected to switchboard 274 byribbon cable 270 and control cord 265. Ribbon cable 270 is containedwithin holster 251. Control cord 265 runs along, and may be attached to,first rotatable shaft 264 and second rotatable shaft 266. Serialcontroller 380 coordinates information exchange across the serialcommunication link between switchboard 274 and microprocessor 408. Anoptional card reader 382 may be provided in control unit 342 for readingdata from memory card in order to facilitate future software upgradesand servicing. A serial port 384 is provided for the bi-directional dataexchange in a serial transmission mode, again to facilitate futuresoftware upgrades and servicing. Serial controller 380 includes a quaddifferential line receiver 524 that is available, for example, as PartNumber DS90C032TM from National Semiconductor Corporation. Serialcontroller 380 further includes an ESD (electrostatic discharge)over-voltage protection array 525 that is available, for example, asPart Number SP723AB from Harris Semiconductor Products.

A first PWM (pulse width modulation) driver 386 interfaces first pinchvalve 314 with microprocessor 408. First PWM driver 386 converts adigital input signal from microprocessor 408 to an analog output signalhaving a wave of fixed frequency and amplitude, but varying duty cycle.To drive the solenoid in pinch valve 314, PWM driver 386 is used whenthe duty cycle is high to initially move the solenoid. Once pinch valve314 is actuated, the duty cycle is reduced to a level, which maintainsvalve position, thus minimizing power requirements. A second PWM driver388 similarly interfaces a second pinch valve 316 with microprocessor408. A suitable example for both first PWM driver 386 and second PWMdriver 388 is FET (60 volt, 3.5 amp, 0.10 ohm, N-channel dual) PartNumber NDS9945 available from Fairchild Semiconductor Corporation.

Referring to FIG. 16B, a first EPLD (Erasable Programmable Logic Device)521 interfaces with LCD controller 404, PWM driver 388, PWM driver 386,an FET 554, oscillator 400, a first 8 MHz. oscillator 538, serialcontroller 380, and microprocessor 408 (via the path represented by theencircled “A” ). A suitable example for first EPLD 521 is available asPart Number EPM7256ATC144-7 from Altera Corporation. FET 554 may beidentical, for example, to FET 556 of second PWM driver 388. Firstoscillator 538 is available, for example, as Part NumberASL-8.000000-PCSA from Abracon Corporation.

A second EPLD 520 interfaces microprocessor 408 with serial port 384,first controller and driver 390, second controller and driver 406, touchscreen controller 402, RAM 392, flash memory 398, and oscillator 540.EPLD 520 is capable of operating at 166.7 megahertz and is available,for example, as Part Number EPM7256ATC144-7 from Altera Corporation.

A third PWM driver 394 interfaces with regulator valve 322 and A/Dconverter 396. PWM driver 394 comprises a voltage reference device 526comprising a first operational amplifier and a voltage reference. PWMdriver 394 further comprises a second operational amplifier 527, a thirdoperational amplifier 528, a fourth operational amplifier 529, a fifthoperational amplifier 530, a sixth operational amplifier 531, and aseventh operational amplifier 532. The operational amplifier in voltagereference device 526, and operational amplifiers 527, 528, 529, 530,531, and 532 are more descriptively referred to as “Quad Rail-to-RailOperational Amplifiers”. A suitable example for each is available asPart Number LMC64841M from the National Semiconductor Corporation. PWMdriver 394 further comprises a first FET (Field Effect Transistor) 553.A suitable example of FET 553 is available as Part Number NDS9945 (60volt, 3.5 amp, 0.10 ohm, N-channel dual) from Fairchild SemiconductorCorporation.

A RAM (Random Access Memory) memory device 392 (also referred to as atemporary memory device) is provided with microprocessor 408, andinherently loses stored data when power is removed. A flash memorydevice 398 (also referred to as a non-volatile memory device), on theother hand, is provided with microprocessor 408 to store data evenwithout power, but it has slower access time than RAM memory device 392.RAM memory device 392 comprises four EDO DRAM devices, 547, 548, 549,and 550. These devices may be identical and a suitable example of eachis available as Part Number MT4LC1M16E5TG-6 from Micron Technology,Incorporated. Flash memory device 398 comprises four RAM devices whichmay be identical and a suitable example of each is available as PartNumber AM29LV800BT-70REC from Advanced Micro Devices, Incorporated. Thecombination of the RAM memory device (temporary memory device) 392, theflash memory device (non-volatile memory device) 398, and microprocessor408 is sometimes referred to simply as a computing device. The computingdevice may also include first controller 523 and second controller 522in an alternate embodiment.

Serial port 384 comprises a dual, universal, asynchronousreceiver/transmitter 533 available, for example, as part numberST16C2552CJ44 from Exar Corporation. Serial port 384 further comprises afirst driver-receiver 534 and a second driver-receiver 535, each moredescriptively called a “TIA/EIA-232, 3×5 driver-receiver” and available,for example, as Part Number DS14C335MSA from National SemiconductorCorporation. Serial port 384 further includes a first transientsuppressor 536 and a second transient suppressor 537 each abidirectional, 24 volt, 300 watt unit available, for example, as PartNumber SMDA24C-8 from General Semiconductor, Incorporated.

Location for an optional card reader 382 interfacing with microprocessor408 is also shown in FIG. 16A. Card reader 382 may be used in futureembodiments of the biopsy device to program control unit 342 withalternate values, for example, of the desired translation and rotationspeeds of cutter 96.

An A/D converter 396 converts voltage signals from pressure sensor 328into digital signals which are transmitted to microprocessor 408, andused by microprocessor 408 to maintain a desired vacuum pressure influid collection system 22. A suitable example of A/D converter 396 isADC-DAC, 8-bit, 12C bus interface available as Part Number PCF8591ATfrom Philips Electronics N.V.

The biopsy device is provided with a conventional, 48-volt DC powersupply used in combination with standard DC-to-DC converters andelectrical voltage regulators in order to supply reduced voltages to thecomponents of control unit 342.

Microprocessor 408 may be used to monitor the output value of secondcontroller and driver 406 PID filter such that if the output of itexceeds a predefined maximum value, the translational speed of cutter 96is reduced a set amount by sending an updated speed command to firstcontroller and driver 390. This closed-loop system insures that thedesired cutter rotational speed is maintained by decreasing thetranslational speed of cutter 96. This automatic adjustment to cuttertranslational speed occurs when cutter rotational resistance becomesabnormally high. Cutter rotational resistance is the combination ofcutting resistance (when cutter 96 encounters obstructions, very densetissue, or calcified lesions, for example) and mechanical resistance(when the operator, for example, manipulates piercer 70 into tissue withenough force to place a significant bending moment on piercer 70 so thatcutter 96 binds inside piercer lumen 80). Rather than attempting tomaintain cutter translational speed by ramping up cutter rotationalspeed, the cutter translational speed is decreased in order to reducethe cutter rotational resistance. In one embodiment of the presentinvention, this is accomplished in the following manner. While in thesampling mode and with cutter 96 advancing toward the third position(proximal to port 78), when cutter 96 reaches a predeterminedtranslational position, microprocessor 408 sends a signal to secondcontroller and driver 406 to initiate cutter rotation. The rotationalspeed of cutter 96 follows a predefined speed profile which insures thatthe cutter rotational speed is at a predetermined Q (also referred to aspredetermined rotational speed) revolutions per minute (rpm) when cutter96 reaches the third position. When cutter 96 reaches the thirdposition, microprocessor 408 sends a signal to first controller anddriver 390 to advance cutter 96 at a predetermined translation speed T(also referred to as a third, predetermined translation speed) inchesper second (in/sec). Cutter 96 then progresses through port 78 atpredetermined translation speed T in/sec while rotating at velocity Qrpm. While advancing through port 78, cutter 96 rotational speed ismonitored by second controller and driver 406, using signals from therotation sensor integrated within rotation motor 338. If the rotationalspeed is greater than Q rpm, electrical current to translation motor 340is increased. If the cutter rotational speed is less than Q rpm,electrical current to translation motor 340 is decreased.

If it is desired to control the speed of either translation motor 340 orrotation motor 338 in response to increased cutter rotation resistance,such as in a further embodiment of the present invention, one way to doso is to generate an error signal based on the difference between thedesired speed (translation or rotation, depending on which motor iscontrolled) and the actual speed. The error signal is then input into aproportional, integral, and derivative (PID) digital filter, which ispart of the respective controller and driver, either first controllerand driver 390, or second controller and driver 406. The sum of thesethree terms is used to generate the pulse width modulation (PWM) signal.First and second controller and driver, 390 and 406, each generate theerror signal and the PWM signal. A PWM signal is input to firstcontroller and driver 390 to generate an analog output signal to drivetranslation motor 340. Similarly, a PWM signal is input to the secondcontroller and driver 406 to generate an analog output signal to driverotation motor 338.

FIG. 15 is an enlarged view of LCD 334 on which messages are displayedduring the calibration procedure of the biopsy system. LCD 334 includesa touch screen 336. LCD 334 and touch screen 336 are part of controlunit 342 of FIG. 14.

As described earlier, during operation of the present invention cutter96 translates between a fully retracted position just proximal to tissuesampling surface 64, also referred to as position 1 (see FIGS. 6A and6B), to a fully deployed position just distal to port 78, also referredto as position 4 (see FIGS. 8A and 8B). Because of manufacturing andassembly differences inherent in each probe assembly 40 it is necessaryfor control unit 342 to “learn” the location of positions 1 and 4 uponstart-up for each new probe assembly 40 operationally connected toholster 140. Once positions 1 and 4 are established all intermediatepositions are readily calculated by control unit 342. It is alsodesirable at initial start-up to rotate cutter 96 to determine if it isoperating within a pre-established acceptable speed range withoutsubject to excessive friction or “drag”.

FIGS. 17A and 17B illustrate a flow diagram for a method of calibrationaccording to the present invention. The steps of the calibration methodare represented in the flow chart. Even though each box may representmore than one step, or may only be part of a step, each box is referredto simply as a step. Progression of the steps occurs generally in thedirection of the arrows connecting the boxes.

Referring first to FIG. 17A, step 410 represents the beginning of thecalibration method. Upon start-up the user is prompted on LCD 334 (seeFIG. 14) to select a probe size. The user does so by touching theappropriate icon on touch screen 336. At step 410 a screen appears onLCD 334 warning of moving parts. At step 411 first controller 523signals first H-bridge motor driver 552 to supply current to translationmotor 340 causing cutter 96 to translate distally toward position 4 (seeFIGS. 8A and 8B). Screw 114 rotates in a direction to cause carriage 124to move cutter 96 distally.

At step 412 control unit 342 is monitoring the movement of cutter 96 byway of signals from encased rotation sensor 268. At step 414, cuttertranslation continues as long as the cutter travel distance is less thanmaximum cutter length “A” programmed into first controller 523 incontrol unit 342. In the present embodiment the value of maximum cutterlength “A” is 5.25 inches, based upon initial user input for probe size.If, as the cutter continues its distal translation, the cutter distancetraveled exceeds maximum cutter length “A”, first controller 523 signalsfirst H-bridge motor driver 552 to terminate current to translationmotor 340 and an error message is displayed on LCD 334 at step 420.

Again referring to step 412, as cutter 96 continues to translatedistally and as long as the distance traveled does not exceed maximumcutter length “A”, eventually distal carriage wall 123 contacts distalscrew support wall 49 halting the translation of cutter 96. This eventforces the rotation of screw 114 to stop. Current is terminated totranslation motor 340 and encased rotation sensor 268 sends a signal tofirst controller 523 which records position 4 at step 416.

After successful completion of step 416, at step 418 first controller523 signals first H-bridge motor driver 552 to reverse rotation oftranslation motor 340, likewise screw 114 reverses rotation, sendingcutter 96 in a proximal direction toward position 1 (see FIGS. 6A and6B).

At step 422 control unit 342 is again monitoring the movement of cutter96. At step 438, cutter translation continues as long as the cuttertravel distance is less than maximum cutter length “B” programmed intofirst controller 523 in control unit 342. In the present embodiment thevalue of maximum cutter length “B” is 5.10″, based upon initial userinput for probe size. If, as the cutter continues its proximaltranslation, the cutter distance traveled exceeds maximum cutter length“B”, first controller 523 signals first H-bridge motor driver 552 toterminate current to translation motor 340 and an error message isdisplayed on LCD 334 at step 440.

Again referring to step 422, as cutter 96 continues to translateproximally and as long as the distance traveled does not exceed maximumcutter length “B”, eventually proximal carriage wall 125 contactsproximal screw support wall 55 halting the translation of cutter 96.This event forces the rotation of screw 114 to stop. Encased rotationsensor 268 sends a signal to first controller 523. Current is terminatedto translation motor 340 at step 423 (see FIG. 17B) and the distancetraveled by cutter 96 between position 4 and position 1 is recorded incontrol unit 342. At step 424, if the cutter translation distance is notwithin a predetermined length tolerance, 5.025″+/−0.075″ for the presentembodiment, based upon initial user input for probe size, an errormessage is displayed on LCD 334 at step 428. Again referring to step424, if the cutter translation distance is within the 5.025″+/−0.075″length tolerance, first controller 523 records position 1 at step 426.

Cutter positions 4 and 1 have now been recorded in control unit 342 forthis specific sterile probe assembly 40/handpiece 20 combination. Slightlength variations due to manufacturing and assembly tolerances from onesterile probe assembly to another have been effectively compensated forby this calibration procedure.

Also, as discussed earlier, at step 424 control unit 342 will computethe distance traveled by cutter 96 between its most distal position andmost proximal position and compare that value with a valuepre-programmed into the memory of control unit 342, to determine if thecorrect probe size is selected for the software residing in the memoryof control unit 342. If the computed value and pre-programmed values donot agree, an error message is displayed on LCD 334 at step 428.

Also, subsequent to the previously described calibration method andduring the actual biopsy procedure control unit 342 uses the valuesrecorded for positions 4 and 1 to calculate the desired distal andproximal stop points for cutter 96. In the present embodiment, duringdistal translation current is terminated to translation motor 340 whencutter 96 is 0.007″ short of reaching position 4. During proximaltranslation, current is terminated to translation motor 340 when cutter96 is 0.006″ short of reaching position 1. This effectively eliminatesthe risk of distal and proximal carriage walls, 123 and 125respectively, impacting the distal and proximal screw support walls, 49and 55 respectively, eliminating the potential for twisting and“winding” of the flexible, rotatable drive cables.

Again referring to FIG. 17B, at step 430 (while cutter 96 is at position1) second controller 522 signals second H-bridge driver 551 to supplycurrent to rotation motor 338 which causes cutter 96 to rotate. Currentsupply is adjusted to the rotation motor 338 in an effort to maintain apre-determined cutter rotational speed. In the present embodiment thepre-determined rotational speed is 200 revolutions per minute (rpm).Actual speed of rotation motor 338 is monitored by second controller 522by way of position feedback provided from the integral rotation sensorin rotation motor 338. The difference between the commanded position andactual position are continually compared by microprocessor 408.Monitoring this difference is a means of establishing the amount ofrotational resistance rotational motor 338 is experiencing due to systemfrictional losses. The larger the difference the greater the systemfriction, possibly indicating faulty system components. At step 432second controller 522 continually adjusts current to rotation motor 338to reach and maintain a speed of 200 rpm for a fixed interval of time.For the present embodiment the fixed interval of time is 3 seconds.

At step 436 second controller 522 adjusts current supply to rotationmotor 338 in an effort to reach and maintain 200 rpm. If, in doing so, apredetermined error count (difference between commanded and actualpositions, which for the present embodiment is 1200 encoder counts) isexceeded before the fixed interval of time is reached, as soon as theerror count is exceeded current is terminated to rotation motor 338 andan error message is displayed on LCD 334.

If, however, rotation motor 338 speed is maintained at 200 rpm for thefixed interval of time (3 seconds) without exceeding the predeterminederror count, current is terminated to rotation motor 338 and “scrollmode” is displayed on LCD 334 at step 434.

The biopsy system is now calibrated and ready for the next operatingmode.

While preferred embodiments of the present invention have been shown anddescribed herein, it will be obvious to those skilled in the art thatsuch embodiments are provided by way of example only. Numerousvariations, changes, and substitutions will now occur to those skilledin the art without departing from the spirit and scope of the appendedclaims.

What is claimed is:
 1. A method for calibrating a surgical biopsy system, said surgical biopsy system comprising a biopsy instrument and a control unit, said biopsy instrument comprising an elongated, hollow piercer, a cutter rotatably and axially positionable relative to said piercer, a port in said piercer for receiving tissue samples, said surgical biopsy system comprising a control unit and a display for providing feedback signals to an operator, said method comprising the steps of: a) translating said cutter distally until translation of said cutter is stopped at an extended position; b) recording said extended position; c) translating said cutter from said extended position proximally until translation of said cutter is stopped at a retracted position proximal to said extended position; d) recording said retracted position.
 2. The method of claim 1 further comprising the step of providing a feedback signal to the operator when said cutter travel exceeds a distance greater than a predetermined value while moving to said extended position.
 3. The method of claim 2 wherein said predetermined value is about 5.25 inches.
 4. The method of claim 1 further comprising the step of providing a feedback signal to the operator when said cutter travel exceeds a distance greater than a predetermined value while moving from said extended position to said retracted position.
 5. The method of claim 4 wherein said predetermined value is about 5.10 inches.
 6. The method of claim 1 further comprising the step of measuring a longitudinal displacement between said retracted position and said extended position, determining if said longitudinal displacement is within a predetermined range, and providing a feedback signal to the operator when said longitudinal displacement is not within said third predetermined range.
 7. The method of claim 6 wherein said predetermined range is about 5.025 +/−0.075 inches.
 8. The method of claim 1 further comprising the step of recording said retracted position in said control unit each time said cutter is subsequently moved to said retracted position.
 9. The method of claim 1 wherein said biopsy instrument is hand manipulatable.
 10. The method of claim 1 wherein said biopsy instrument is detachably fixed to an imaging machine.
 11. A method for calibrating the rotation of a cutter of a surgical biopsy system, said surgical biopsy system comprising a biopsy instrument and a control unit, said biopsy instrument comprising an elongated hollow piercer, a cutter rotatably and axially positionable relative to said piercer, a port in said piercer for receiving the tissue sample, said surgical biopsy system comprising a control unit and a display for providing feedback signals to an operator, said method comprising the steps of: a) rotating said center to a rotation speed while said cutter is located at a retracted position; b) determining if said rotation speed is reached and maintained within a fixed time interval; c) providing on said display a feedback signal allowing the operator to progress to the next procedural step when said rotation speed meets predetermined parameters.
 12. The method of claim 11 further comprising the step of providing a feedback signal to the operator when said rotational speed is not within said predetermined parameters.
 13. The method of claim 11 wherein said biopsy instrument is hand manipulatable.
 14. The method of claim 11 wherein said biopsy instrument is detachably fixed to an imaging machine.
 15. The method of claim 11 wherein said fixed time interval is about three seconds.
 16. The method of claim 11 wherein said rotation speed is about 200 revolutions per minute.
 17. A method for determining that the correctly sized biopsy instrument has been selected by an operator for a surgical biopsy system, said surgical biopsy system comprising a biopsy instrument and a control unit, said biopsy instrument comprising an elongated, hollow piercer, a cutter rotatably and axially positionable relative to said piercer, a port in said piercer for receiving tissue samples, said surgical biopsy system comprising a control unit and a display for providing feedback signals to an operator, said method comprising the steps of: a) translating said cutter distally until translation of said cutter is stopped at an extended position; b) recording said extended position c) translating said cutter from said extended position proximally until translation of said cutter is stopped at a retracted position proximal to said extended position; d) recording said retracted position; e) computing in said control unit total distance traveled between said retracted position and said extended position by said cutter; f) providing on said display a feedback signal to the operator when said total distance traveled falls outside a predetermined range. 